Drug therapies are a primary component of an overall patient health plan. Drugs or therapeutic agents can be delivered to a patient in various ways including oral ingestion, intramuscular and/or intravenous injection or topical absorption. Most of these approaches require administration by medical professionals or regular patient compliance with the drug regimen. In addition, these drug delivery approaches, although useful, are not very effective in delivering therapeutic agents to internal body tissues or organs.
Drugs and therapeutic agents can also be administered through the use of catheters. Catheters are medical devices designed for insertion into a body passageway that facilitate injection or withdrawal of fluids into a patient's body. Catheters provide an advantage of direct vascular and/or local delivery of a therapeutic agent to body tissues and organs that can include the heart, esophagus, stomach, large intestine, and other tissues which may be accessed via a catheter system. Catheters and catheter systems can deliver drugs to the sites where they are most needed, reduce the amount of medication required, and improve the control over the time for delivering the drug. However, drug deliver using current drug delivery devices can be problematic in that certain problems, such as the growth of tissue over the catheter opening, control of the fluid flow rate of the drug being administered, and resistance from other bodily fluids when introducing the drug need to be addressed.
One approach to overcoming some of these drawbacks is to use an implantable infusion pump. Implanted infusion pumps usually include a pressurized drug reservoir and a form of fluid flow control. However, for some applications, implantable infusion pumps are inadequate because the amount of the therapeutic agent required for delivery and the need for additional pressure exceed the capability of most infusion pumps. Redesigning the infusion pump to address these deficiencies substantially increases the cost and size of the device.
There is a need for a drug delivery system for administering drug therapies that can be used with conventional, implantable infusion pumps and catheters, and that addresses the aforementioned problems, as well as other related problems.